If your transaction still unconfirmed or stuck the link is already posted by hugeblack or go directly here https://www.viabtc.com/tools/txaccelerator/
Anyway, it looks like he doesn't need to wait for more than 24 hrs because the transaction is already received more than 10 confirmations.
Next time learn to check the current recommended fee from https://bitcoinfees.21.co/ and https://coinb.in/#fees but since Bitstamp doesn't have an option to set up the fee these tools are useless but you can refer on this to know if there is network congestion or if the fee for a faster transaction is low or high.